tag:blogger.com,1999:blog-4348292068036323235.post675979676090601292..comments2023-08-29T03:53:29.334-07:00Comments on Bones Hi - Fi: Germanium Transistor Based Audio Power Amplifiers: High Fidelity’s Undiscovered Country? Ringohttp://www.blogger.com/profile/09506068154852505840noreply@blogger.comBlogger11125tag:blogger.com,1999:blog-4348292068036323235.post-39055467608716468722021-01-11T18:49:22.524-08:002021-01-11T18:49:22.524-08:00I see there is an interest in amps based on the AD...I see there is an interest in amps based on the AD149. According to |<br />https://www.radiomuseum.org/tubes/tube_2n555.html<br />the AD149 is a substitute for the 2N555. I recently came across a dozen Motorola 2N555 TO-3 with a date code of 5-12. Instead of selling them on eBay I'd rather restore some equipment which is in need of them. If anyone can point me to a resource with a list of equipment likely appropriate for restoration with 2N555s please share. One BIG issue is the 2N555 is max V C-E, C-B is only 30 where the AD149 is 50, so AD149 based equipment will probably fry these. I'd need to go a little older yet. If you can't find me here I am JBurdman7 on most online platforms, Yahoo mainly. Thanks in advance.JBurdman7https://www.blogger.com/profile/00082399926982097371noreply@blogger.comtag:blogger.com,1999:blog-4348292068036323235.post-82113770341832270912019-12-28T19:21:58.559-08:002019-12-28T19:21:58.559-08:00Have question: I using 2sb407 in my transformer co...Have question: I using 2sb407 in my transformer coupling amp. Some people say they are old early transistors not good. I try ad150 which sound was also greate and more hi frequency. But only 3.5 amp. 2sb407 has 7amp. Al102, 103 I didn't like to fragile and sound like silicone or require more bias....<br />What the best American Germanium which<br />handle up to 50watt and 0.5-1mhz ???Anonymoushttps://www.blogger.com/profile/05235015781515357793noreply@blogger.comtag:blogger.com,1999:blog-4348292068036323235.post-55833469637332692042019-05-19T19:22:44.874-07:002019-05-19T19:22:44.874-07:00Hi,JFStumper I would definitely be interested in a...Hi,JFStumper I would definitely be interested in a germanium amp, class A. Ten watts is plenty, budget 400.00<br /> New Germanium Transistors are in production.<br />http://www.comsetsemi.com/en/index.phpelocohttps://www.blogger.com/profile/11194495075748756613noreply@blogger.comtag:blogger.com,1999:blog-4348292068036323235.post-25509574448818881332019-05-12T01:04:04.547-07:002019-05-12T01:04:04.547-07:00 JF stumper I would defintely be intersted in a hi... JF stumper I would defintely be intersted in a high quality GE amp kit.elocohttps://www.blogger.com/profile/11194495075748756613noreply@blogger.comtag:blogger.com,1999:blog-4348292068036323235.post-41461714896440735792016-03-31T18:23:49.688-07:002016-03-31T18:23:49.688-07:00Hello, just found this post when Googling germaniu...Hello, just found this post when Googling germanium. I recently bought an Armstrong 521 amp at a garage sale and to my surprise it is one of the sweetest and most detailed amps I have heard. It also has an astonishing bottom end. This led me to think that maybe it is due to the transistors. There is definitely something to be learned here. BTW, it runs fairly cool. Thanks for the info.speedy_steelhttps://www.blogger.com/profile/04568818986162076124noreply@blogger.comtag:blogger.com,1999:blog-4348292068036323235.post-51449441141475130512015-03-31T04:33:53.867-07:002015-03-31T04:33:53.867-07:00I've done this 20 years ago using surplus heat...I've done this 20 years ago using surplus heat-sinks twice the area of a broadside of a brad-toaster and it does go very hot - Hot enough to Hibachi an egg 1980s style. Probably 80-percent of the 100-watt power supply is converted to heat while 20 percent goes into amplification and probably only 10 percent is converted into actual acoustic output. It did look like one of those solid-state class-A amps from DNM and Pass Laboratories. Sadly, I don't know where I hid it. I've tried Japanese PNP germanium transistors which are more common but they also run hotter than premium types and tend to self destruct unless if you probably use a microprocessor based biasing scheme used by Mark Levinson or Krell on their mega-buck amplifiers. Ringohttps://www.blogger.com/profile/09506068154852505840noreply@blogger.comtag:blogger.com,1999:blog-4348292068036323235.post-5655370957829605792015-03-29T03:48:45.235-07:002015-03-29T03:48:45.235-07:00I am currently also looking after the idea of a Ge...I am currently also looking after the idea of a Ge-Amp. You simply can't buy one, not even a DIY kit.<br /><br />The benefit of high slew-rate sounds plausible, the power stage is quite linear and doesn´t need the feedback loop of a Si-stage: this removes the slew rate limit. The AD149 limits the power due to the low voltage, but a modern "BTL" design can double the power at same voltage. <br /><br />Would anyone be intetested in a modern state-of-the-art Germanium Amp? How much power do you need and what is the budget?JFStumperhttps://www.blogger.com/profile/04247325211107904465noreply@blogger.comtag:blogger.com,1999:blog-4348292068036323235.post-26688025587881941932015-03-29T03:48:28.668-07:002015-03-29T03:48:28.668-07:00This comment has been removed by the author.JFStumperhttps://www.blogger.com/profile/04247325211107904465noreply@blogger.comtag:blogger.com,1999:blog-4348292068036323235.post-68619543607861056592014-11-22T13:56:34.317-08:002014-11-22T13:56:34.317-08:00Just found this post recently. I'd really like...Just found this post recently. I'd really like to know just how anyone ever got 10 single ended watts out of an AD149? I would imagine this involved a transformer. Where in the heck did they find that and where can I get one...or two for that matter? I've searched high and low for push pull transformers used back in the day with 2n301's, of which I must have over 100 and could not find anything that would even cross to old part numbers I found.emdudehttps://www.blogger.com/profile/02140518569571597366noreply@blogger.comtag:blogger.com,1999:blog-4348292068036323235.post-52686460784244911032013-05-12T00:06:23.472-07:002013-05-12T00:06:23.472-07:00Did Mullard ever made a more reliable version of t...Did Mullard ever made a more reliable version of the stock failure prone selenium rectifier of the Fisher 500-C receiver, Lilith Fair? Ringohttps://www.blogger.com/profile/09506068154852505840noreply@blogger.comtag:blogger.com,1999:blog-4348292068036323235.post-67614244479400185832013-05-11T02:51:25.497-07:002013-05-11T02:51:25.497-07:00Mullard managed to manufacture their own version o...Mullard managed to manufacture their own version of the AD 149 PNP germanium output power transistor in a TO-3 package. I've heard do-it-yourself single-ended germanium transistor based audio power amps during the mid 1990s and to my ears, they sound as if they have almost unlimited slew rate - as in 5-million volts per microsecond. Especially when playing Veruca Salt tracks in both vinyl and CD form. Lilith Fairhttps://www.blogger.com/profile/11390564952244642802noreply@blogger.com